This invention relates to a system for monitoring a characteristic of a product and in particular to a system of monitoring a characteristic of concrete in a concrete testing process to thereby monitor the quality of supplied concrete.
Presently, ready mixed concrete in produced at a batching plant and transported to a construction site by trucks. At the construction site, a sample of concrete is taken from one in about six trucks. The sample is subjected to the performance of a series of tests to monitor the quality of supplied concrete. The tests performed on a concrete sample are usually a slump test and a compression strength test. The sample of concrete is taken from the truck and wheelbarrowed into a xe2x80x9ctest cube making centrexe2x80x9d.
A slump test is performed on the sample of concrete and the result is recorded manually into a log book. A slump test is a measure of concrete workability. The test is performed by filling a specially shaped metal cone with concrete to be tested, removing the metal cone so that the cone of concrete partially subsides or slumps, and measuring the change of height of the concrete from the height of the top of the cone to the height of the top of the slumped concrete pile. Generally speaking, the greater the change in height, the greater the workability of the concrete.
To prepare the concrete for compression strength testing, about six test cubes of dimension of 150xc3x97150xc3x97150 mm are made. Normally, three of the test cubes are stored for seven days while three are stored for twenty-eight days. In the current system, when the test cubes are made, a written paper note which includes information such as the date the test cube was made, the grade of concrete, the test cube number and what load of concrete the test cube came from, is placed on top of the test cube while the test cube is still wet. The next day, when the concrete has cured, the mould used for making the concrete test cube is removed and the information from the note attached to the test cube is transcribed to the side of the test cube using a crayon or permanent marker.
After storing the test cubes for an appropriate number of days, the test cubes are tested for their compression strength and their measurements are recorded manually into the log book which contains the slump test results. In most cases, after the compression strength test is conducted, the test results are also manually entered into a computerised database.
Occasionally when the requirements for the concrete deviate from normal, adjustments are made to the testing conditions. For example, the test cube dimensions may need to be changed to 100xc3x97100xc3x97100 mm. In addition to the standard seven day and twenty-eight day compression strength tests, the test cubes might need to be tested for their two day, three day and/or fifty-six day strength. In this case, additional test cubes will need to be made for testing.
There a number of problems with the current testing system. Firstly, due to the manner in which information is recorded, information relating to the test results can be lost or interfered with. For example, as discussed above, information in recorded on paper notes which are placed on the concrete test cubes. While the information is usually written using a permanent marker, the data can be smudged or become faded if the note gets wet or dirty. Concrete test cubes are often submerged in water as part of the curing process adding to the likelihood of data being lost on other occasions, the note can become detached from the test cube and it is not always be possible to match a detached note to a particular test cube. Particularly, if more than one note becomes detached at the same time. As a result, when data identifying the test cube needs to be transferred onto the side of the test cube, the data can be distorted or lost.
Other errors arise due to errors in the transcription of data from the notes to the sides of the test cube.
Even if the data is transcribed accurately from the note to the side of the cube, it is possible for the writing on the side of the cube to become smudged or at least degraded sufficiently to make it hard to read to recover the data.
Furthermore, it is easy to tamper with the information on the note or on the side of the cube or when it is being entered into the log book. Thus, data might be changed in order to meet safety standards or to cut costs.
Further errors arise due to manual recording of the test cube data, slump tests and compression strength test results and also when the information is transferred from the log book to the computerised database. To attempt to improve the accuracy of the data it is often necessary for the data to be double checked which can consume time and increase the cost of the process.
Furthermore, in the current system it is necessary for both a client representative and a contractor to be present to witness the compression strength test. This is extremely resource intensive.
A further problem is that because of the delay between recording the data into a log book and transferring the data onto a computer database, the database is not readily accessible from the computerised database in a reasonable time frame for analytical purposes. Occasionally, the time is often increased because contractors tend to misplace log-books.
The above mentioned problems can have serious consequences in relation to monitoring the quality of concrete. It will be understood that it is important to ensure that concrete is of sufficient quality because there are potentially serious ramifications for the structure made from the concrete if the quality is inadequate. For example, if a compression strength test indicates that a particular batch of concrete is flawed to the extent that it may cause problems in the finished structure which employs the concrete, then it is important that such a result can be related to where the concrete has been used in the actual structure. If information relating to the particular test cube is lost or incorrect, it may not be possible to make this connection or the connection which is made may not be correct. Furthermore, as the current system requires manual entry of data, it is possible for the person entering the data to interfere with it and modify the test results when they do not meet safety criteria.
Embodiments of the present invention attempt to address the foregoing problems and at least to provide a system which is improved compared to the current system.
The invention provides a system for monitoring a characteristic of a product in a testing process, said system including:
an information storage device for storing information relating to said product, said information storage device being separate from said product and adapted to be affixed to said product;
writing means for writing said information to said information storage device;
reading means for reading said information from said information storage device and storing said information in a database; and
test means for performing a test on said product to produce a test result and storing said test result in said database so that it is associated with said information, whereafter the associated information and test result stored in said database enable monitoring of the characteristic of the product.
Preferably, said product is produced at a first location and transported to a second location before said information storage device is affixed to said product.
Preferably, said product is transported to said second location together with identification data associated with said product, and wherein said identification data is inputted to a memory of said writing means at said second location, said identification data being subsequently written to said information storage device by said writing means as at least part of said information.
Preferably, a preliminary test is conducted on said product at said second location and a preliminary test result of said preliminary test is inputted to said writing means, said preliminary test result being subsequently written to said information storage device by said writing means as at least part of said information.
Preferably, separate input means are provided for imputting said identification data and said preliminary test result to said writing means.
Preferably, said identification data is encoded in a bar code and said writing means includes a bar code reader to enable said identification data to be inputted to said writing means.
Preferably, said writing means includes a key pad and said key pad is used to input at least said preliminary test result.
Preferably, said writing means writes said information to said information storage device after said information storage device is affixed to said product.
Preferably, said writing means writes said information to said information storage device before said information storage device is affixed to said product.
Preferably, said system further includes storage means for storing said product after said information storage device has been affixed to said product and said information has been written to said information storage device, and wherein said product is retrieved from said storage means before said reading means reads said information.
Preferably, said product is in a first state when said product is produced and in a second state when said test is performed on said product.
Preferably, said product is concrete and the concrete is fluid in said first state and is solid in said second state.
Preferably, said concrete is formed into a test cube and said test is performed on a solid test cube.
Preferably, said preliminary test is a slump test.
Preferably, said test means performs a compression-strength test on said solid concrete.
Preferably, paid system includes weighing means for weighing said product before said test means performs said test and storing the weight of said product in said database go that the weight of said product is associated with said test result and said information.
Preferably, said reading means reads said information when said product in located in a testing position where said test means can perform said test.
Preferably, the information in said information storage device cannot be altered after the information is written to said information said storage device by said writing means.
Preferably, the information written to the information storage device includes a time at which said information written to said information storage device.
Preferably, said identification data includes at least one of:
a date delivery;
a time of delivery;
a customer name;
a location of a customer""s site;
a product description;
a delivery note number;
an internal order number;
an internal vehicle number;
a register vehicle number;
a total amount ordered;
an amount of a load;
an amount of the total amount ordered which has delivered;
an amount of the total amount still to be delivered;
additional charges;
who issued the product; and
who ordered the product
Preferably, the information written to the information storage device includes at least one of:
a date of making of a test cube;
a time of making of a test cube;
a slump test result;
a grade; and
a test cube number.
Preferably, said writing means generates a radio frequency information signal to write said information to said information storage device.
Preferably, said writing means is a hand held device.
Preferably, said reading means includes a reference signal generator and a receiver, and said information storage device includes retransmission means) wherein, in use, said reference signal generator generates a reference signal, said retransmission means alters said reference signal so that it contains the information stored on said information storage device to thereby produce an altered reference signal which is received by said receiver, whereafter said reading means extracts said information from said altered reference signal.
Preferably, said retransmission means is a passive device.
Preferably, said information means is a transponder.
Preferably, signals are radio frequency signals.
The invention also provides a system for testing concrete including using the above system for monitoring a characteristic of a product in a testing process, wherein the product is a sample of said concrete which is tested to thereby monitor said concrete.
Preferably, a plurality of samples are tested.
Preferably, the compression strength of said concrete is monitored.
Preferably, concrete from approximately one out of every six truckloads of concrete delivered to a site is tested.
Preferably, the slump test result of said concrete is monitored.